An interview with Raven Software's Kenn Hoekstra at Daily Radar provides new details on the as yet unnamed add-on pack for Star Trek: Voyager - Elite Force.
As far as the new single-player elements go, we have the Virtual Voyager mode (or tour mode, as it was originally known), featuring all of the major areas of the USS Voyager. You can interact with the crew and the environment as well as read ship's logs and technical information. There are mission objectives as well, and a hunt to find 14 secret items. We also have several Holo-Missions built in to the Virtual Voyager mode, including a Captain Proton mission, a Klingon stealth and infiltration mission, a firing range and a garden relaxation program that goes awry. These combine for a total of 16 new single-player maps, if you include the Voyager levels that are part of the tour.